Various types and combinations of petroleum products are used as starter fuels for charcoal, wood and other fuels. A popular type is Wizard.RTM. brand charcoal lighter from Boyle-Midway, Inc. of New York, N.Y. which burns quite completely, but is highly flammable and can be extremely dangerous. In some cases the petroleum starter fuel may only partly impregnate the edges of charcoal which then burns incompletely, causing a petroleum odor that penetrates the cooked food. Explosive burning can result when these liquid petroleum starters, which have a low flash point, are sprayed on hot coals. Severe burning and in some cases death has resulted from the use of such liquid fire starter products.
Other types of charcoal and wood starters have been developed that are less dangerous, some of which consist of wax impregnated sawdust, wood or fiber particles. These starters are usually more costly to produce and can impart a waxy odor and taste to food if incompletely burned.
The product composition of said invention, on the other hand, ignites easily and burns completely, thereby enabling the charcoal or wood to burn without the necessity of attempting a dangerous "second start". If a "second start" becomes necessary, the oil impregnated dried wood chips can be added with a low risk, since the vegetable oil, resin, wood combination has a high flash point.
Green wood chips and bark are consumed in large quantities by paper mills and other wood processing plants. These wood products have a high moisture content, usually from 45 to 55 percent, and low energy content of about 4,000 BTU/lb. As a result of this high moisture content, an auxiliary fuel such as natural gas, fuel oil or coal is required to obtain the necessary flame temperatures for heating and producing steam. Green wood chips are also increasingly used as a heating fuel for schools, hospitals, manufacturing facilities and public buildings, but the high moisture content of the wood increases freight and operating costs while limiting the efficiency and output of the furnace.
The product composition of said invention, on the other hand, contains a high energy content, varying from 8,500 to 11,500 BTU per pound, and ignites and burns completely, thereby substantially reducing or eliminating the need for auxiliary fuels. The transportation costs, based on delivered BTU's is reduced because water content of the fuel has been substantially reduced, in some cases to the 2-3% level.
The impregnated oil also protects the wood product from reabsorbing moisture. The wood product can, therefore, be stored outside.
Green wood chips typically contain from 45 to 55 percent water. Attempts to dry such wood chips in a kiln or similar device to a low moisture content are inhibited by the tendency of the wood material to char and burn if heated to too high a temperature. Such drying takes an extremely long period of time if the temperature is too low. At low drying temperatures it is also difficult to reach moisture levels of below 10%. Above a moisture level of about 10% the ignition rate of the wood particles is lowered.
The drying required to produce a satisfactory starting material from wood chips requires the removal of both the surface moisture and interstitial water.
Most wood types, including softwood and hardwood or blends of wood types can be satisfactorily dried by the teachings of this invention. However, tests conducted on hot vegetable oil dried wood chips of separate varieties has shown that wood chips of the genus pinus (pine) will ignite faster and burn more readily than wood chips of other varieties, i.e. trembling aspen (poplarus trembli) or birch (genus Betula), oak (genus Quercus), or maple (genus Acer) and are, therefore, more suitable as a starter fuel. This is because pine contains greater quantities of resin and pitch which, when combined with impregnated, entrained vegetable oils starts quicker and burns more readily.
Oils, other than vegetable or palm oil can be used including petroleum oil to obtain the necessary fast starting qualities required, but these oils leave distasteful odors and generate substantially more smoke and soot. Wood chips prepared by drying in hot vegetable and palm oils burn cleanly with little perceptible odor and smoke.
It is highly desirable that charcoal and wood starters be safe while stored in warehouses and on display in retail establishments. High volatile, petroleum based starters are very dangerous and punctured containers caused by errant fork lift handling, droppage or other handling problems, and temperature changes will result in spillage thereby creating dangerous highly flammable situations. This could, in addition to creating a dangerous situation, result in increased insurance rates and/or directives to warehouse and display these materials in specially designated locations.
On the other hand, oil dried wood chips can be safely stored and handled. A broken bag or case may be picked up with a broom and shovel and discarded in standard trash units due to the low volatile nature of the products of the invention.
Petroleum starters are also extremely poisonous and caution must be taken in handling and in placing and keeping the container out of the reach of children. Oil-dried wood chip starters on the other hand contain only wood and vegetable oil, are basically non-toxic and can be handled without the inherent dangers of petroleum starters.
The use of wood starters of the invention instead of petroleum starters could save many lives and prevent thousands of burn injuries.
Others have tried to prepare charcoal and wood starters by first drying wood sawdust and impregnating the sawdust with wax. In Dehart et al U.S. Pat. No. 4,147,518, paraffin waxes are utilized at a ratio of about two parts wax to one part wood.
Wood chips prepared for use as an industrial or home heating fuel can be dried using low cost fuel oil, waste oil or combinations. Wood chips dried in waste oil provide a very high BTU fuel, varying from 10,500 to 11,500 BTU/lb., which ignites and burns readily. Such products are highly usable fuels and also represent an environmentally safe method of utilizing and thereby disposing of waste and used oil since the dried wood contains from about 5 to about 35 percent and more, preferably about 10 to 30 percent impregnated oil, yet is practically "dry" to the touch. The waste oil in effect is converted from a difficult to handle, messy and sometimes nearly toxic fuel to a safe, easily handled, readily burnable fuel.
It was also discovered that when certain wood types, i.e. trembling aspen (poplarus trembli) are dried in No. 5 residual fuel oil, that the combustion air can be controlled to produce a fine, carbon laden soot which can be collected as carbon black. The quality of the carbon black collected is similar to that obtained during the production of carbon black from the incomplete combustion of natural gas which is a major source of carbon black. Carbon black produced by the subject invention would be lower in cost and conserve dwindling quantities of natural gas.